Solar-Powered Wireless Charging Grids

The transportation industry accounts for the second highest producer of greenhouse gases, with 28% of all greenhouse gas emissions. The most abundant of these are gasoline-powered cars, with their carbon dioxide emissions. More recently, electric battery powered cars have hit the market. While they do not directly emit greenhouse gases, they are very inefficient and need to be charged often, usually through a wall electrical outlet that is powered by a coal plant. To fix this, we have devised a method in which electric cars could be charged while on the road, using what we call “wireless charging grids”. These charging grids would consist of metal induction panels placed under the roads. They would be powered by photovoltaic cells at the side of the road. On the receiving end, the electric cars would use built in induction panels underneath the chassis. As the cars drive over the charging grid, they capture the electricity to charge the battery. This would be efficient as the car is in close proximity to the road. The charging grids could be placed under existing highways and would span about 2000 feet and be spaced every 2 miles. At a typical highway speed limit of 60 miles per hour, an electric car would pass over the charging grid for approximately 22 seconds. This technology could help those who travel long distances to make the switch to electric cars.

Solar-Powered Wireless Charging Grids

The transportation industry accounts for the second highest producer of greenhouse gases, with 28% of all greenhouse gas emissions. The most abundant of these are gasoline-powered cars, with their carbon dioxide emissions. More recently, electric battery powered cars have hit the market. While they do not directly emit greenhouse gases, they are very inefficient and need to be charged often, usually through a wall electrical outlet that is powered by a coal plant. To fix this, we have devised a method in which electric cars could be charged while on the road, using what we call “wireless charging grids”. These charging grids would consist of metal induction panels placed under the roads. They would be powered by photovoltaic cells at the side of the road. On the receiving end, the electric cars would use built in induction panels underneath the chassis. As the cars drive over the charging grid, they capture the electricity to charge the battery. This would be efficient as the car is in close proximity to the road. The charging grids could be placed under existing highways and would span about 2000 feet and be spaced every 2 miles. At a typical highway speed limit of 60 miles per hour, an electric car would pass over the charging grid for approximately 22 seconds. This technology could help those who travel long distances to make the switch to electric cars.

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Judges’ Queries and Presenter’s Replies

Arturo Gutierrez

Judge

June 8, 2015 | 02:15 p.m.

Good idea building on the concept of wireless cell phone charing stations. I appreciate that you recognize that electric vehicles still use energy from the grid and, therefore, still contribute to CO2 emissions. I have several questions regarding your idea.

1. Why did you chose to have the charging stations on the roads versus stationary charging? Pros and cons of each?

2. Do you have a sense for how large of a battery you would need to charge 100 cars per day? 1000 cars per day? 10,000 cars per day?

3. Do you have a sense for the area needed to charge a battery capable of charging 100 cars per day? etc.

Calvin Kinzie

Co-Presenter

June 8, 2015 | 09:56 p.m.

1: The charging stations can be implemented anywhere. We have them on major highways since it allows for electric cars to travel longer distances, as this is a very big issue for them. However, we could also implement them in stationary areas, most notably parking lots. This has the advantage of keeping the cars charging longer, but does not help on a longer trip (such as a travel through route 89).

2/3: Yes. The battery would have to be much larger than is practical to completely charge this many cars. However, that is not what we intend to do. Our system is both spaced out so that there are smaller, more frequent batteries. It also is intended to give a boost of energy to a car for its duration, as opposed to charging it completely. Assuming an electric car takes 12 kWh to charge for 24 hours of use, the battery would be anywhere from 5kg to as low as 1kg per car, using recent battery technology like IBM’s Battery 500, which would have a roll-out time that matches ours. Using more conventional batteries, which we want to avoid, we would be closer to the 5 kg mark. This would cost around $100 per kWh. Although this seems expensive, again, we are only partially charging the cars, using less and reducing this. In terms of area, it would vary based on how large the solar farms are, but we cannot give an exact estimate, we can say with certainty is would be smaller than the size of the charging grids.

I really like your idea of having electric cars charge while they drive and of using solar energy to provide the electricity to charge the cars. I have two questions on your design:

1) You state that the cars will travel over the charging in approximately 22 seconds, do you have an idea of how much energy can be transmitted during that time compared to the amount of energy used by the car during that time?

2) Have you considered the extra weight and cost to the car of implementing the induction coils? Will these factors likely have a negative impact on the performance and adoption of electric cars?

Calvin Kinzie

Co-Presenter

June 9, 2015 | 05:46 p.m.

1: The important thing isn’t how much time it travels over each grid, it’s the grid frequency. As of right now, the plan is to have the grids cover roughly 1/5 of the road (1/2 mile every 2 miles). It would charge, then, at slightly less than 1/5 of the normal charging rate as if it were charging off of AC or DC power. Although this does not seem like much, it is a huge difference in energy savings and helps with long trips immensely.
2: Yes. They will be fairly light, and while we cannot give an exact estimate, since they are thinly applied on the bottom and are mostly copper, metal, and plastics, they will weigh somewhere in the vicinity of 15-40 kg. This is not significant enough to have a performance impact.

Daniel Jones

Judge

June 9, 2015 | 10:08 p.m.

A fascinating approach to increasing the range of battery only cars and getting coal’s role reduced in the recharging process. This might encourage more people to go electric, plus the energy would be carbon-free, both of which would be great for the environment. Battery improvements and shorter recharging times might be your biggest competition. How do you envision the future of SolCharge as battery technology improves?

Calvin Kinzie

Co-Presenter

June 10, 2015 | 04:37 p.m.

Rather than harm our project, we would work with it. Our charging is limited by the car’s maximum electrical intake. If car batteries and recharge rates were to improve, our project would be even more effective at charging the cars. The only issue is that if cars were to drain faster than our batteries or solar farms could provide, we would have an issue which would have the road need better batteries or more solar panels, but that is hot-swappable so it is not too much of an issue to fix. However, such a situation is not in the foreseeable future.

You mention that electric cars still rely on fossil fuels and natural resources. Could you explain the ways in which a fully electric car is still reliant on these? How would SolCharge get around the need to use traditional fuels during production, transportation, and installation?

Calvin Kinzie

Co-Presenter

June 10, 2015 | 04:15 p.m.

A fully electric car is, while not necessarily reliant on traditional fuels, almost always using electricity from a coal, natural gas, or at best, nuclear plant. The electric cars that do not rely on electricity from these sources are almost always run from the owner’s own renewable energy, which is often too expensive or impractical for most to adopt. I would advise you to look at this for more info: http://www.afdc.energy.gov/vehicles/electric_em...

As for SolCharge getting around the need to use traditional fuels during production, transportation, and installation, we would not ever be able to eliminate that completely. However, there are two things in consideration. First, we would build SolCharge with recycled materials to avoid production issues on one front. Second, SolCharge ends up making up in energy and fuel expenditure with the energy it generates on the road.

Further posting is closed as the competition has ended.

Presentation Discussion

Callie Cook

This idea is very good. However I am concerned about the feasibility of it. You said that the charging grids will be placed under the highways. This will be very expensive. Do you plan on putting them everywhere or only major highways? It would be very difficult to put these charging grids on every highway across the country. How do you plan on installing them? Will you have to shut down the high way while installing them? If so that my cause some problems. How much would this car cost? What are some selling factors to convince a consumer to purchase your car instead of all the other cars on the market today?

Calvin Kinzie

Co-Presenter

June 8, 2015 | 10:12 p.m.

Putting them everywhere would be, as you said, a huge expense. We are only planning to place them on major highways for about 1/5 of the road (1/2 mile every 2 miles). This helps with price.

Installation would be done in 3 steps fairly quickly. First, The solar farms would be placed on the side of the road. We would then dig trenches on the sides to store the batteries in, and wire them to the solar farms. This would be done without the need to stop the highway. The next step is tricky. We would lay the charging grids down as fast as possible and then wire. On sparse highways, this is doable without shutting down the highway. However, on busier highways, we would require a brief (<1 hour) shutdown to place the charging grids and ensure security. This would require a detour, and would be done in chunks to ensure traffic could flow.

This would simply be an augment to electric cars, raising the price over a typical electric by roughly a couple hundred at most.

Selling factors are the obvious environmental benefits, but also the immense amounts saved on gas and power, which in the long run will end up saving them money.

Callie Cook

If I were to purchase this car would I have to rely entirely on charging it on the road? What happens if I own one of these cars but I’m driving on a highway without SolCharge? Is there an alternative charging method?

Calvin Kinzie

Co-Presenter

June 9, 2015 | 03:33 p.m.

No, not at all. SolCharge is simply an augment to electric or hybrid cars, which means you can still charge them offroad however you would charge them normally.

Callie Cook

Divya Gandla

Wow, this is a very interesting idea. If a cost-effective plan for the wireless charge grids could be designed, it could serve as a ground-breaking innovation to counteract the effects of greenhouse gases originating from car fumes. The switch to electric cars would be very attractive to Americans if your highway charging grids could be implemented. However, there are still some concerns to address. How much do you approximate the turnover to the charging grids will cost? How will the energy be transmitted between the photovoltaic cells and the induction panels? Will this innovation be implemented only on certain highways with a minimum speed limit? If so, what average speed should the cars be traveling at to optimize the energy output?

Calvin Kinzie

Co-Presenter

June 8, 2015 | 10:48 p.m.

Cost varies by the size of the solar farms, how far spaced apart the charging grids are, and the battery size, which vary based on the road activity. However, we can give you a breakdown by part. As a background, we plan to place the grids (mostly) for 1/2 mile every 2 miles.

The solar farms are going to be purchased in industrial quantities, which would be around $0.70/W (plus maintenance), or $700/kW. The batteries would cost around $100 per kWh, and we would have between a dozen to multiple dozen kWh (varies strongly). As for the changing grids, we do not yet have a definite estimate.

One should keep in mind the money that is saved in energy costs by our idea when looking at our project.